func DateFmtTool()

in tools/datefmt.go [63:118]
45 lines of code
11 McCabe index (conditional complexity)

func DateFmtTool(args []string) error {
	os.Args = args

	flag.Usage = func() {
		fmt.Println(MarkdownHelp("datefmt"))
	}

	flag.BoolVar(&helpFlag, "h", false, "print this help info")
	flag.BoolVar(&helpFlag, "help", false, "print this help info")
	flag.Int64Var(&timestampFlag, "t", time.Now().Unix(), "unix timestamp to convert")
	flag.Int64Var(&timestampFlag, "timestamp", time.Now().Unix(), "unix timestamp to convert")
	flag.StringVar(&strFlag, "s", "", "date string to convert")
	flag.StringVar(&strFlag, "str", "", "date string to convert")
	flag.StringVar(&iFmtFlag, "if", "", "input format to use")
	flag.StringVar(&oFmtFlag, "of", "UnixDate", "output format to use")
	flag.StringVar(&oFmtFlag, "f", "UnixDate", "output format to use")

	flag.Parse()

	if helpFlag {
		flag.Usage()
		return nil
	}

	ofmt, ok := dateFormats[oFmtFlag]
	if !ok {
		return fmt.Errorf("error: invalid output format: %s", oFmtFlag)
	}

	if strFlag != "" && iFmtFlag != "" {
		ifmt, ok := dateFormats[iFmtFlag]
		if !ok {
			return fmt.Errorf("error: invalid input format: %s", iFmtFlag)
		}

		currentDate, err := time.Parse(ifmt, strFlag)
		if err != nil {
			return err
		}

		fmt.Println(applyFormat(currentDate, ofmt))

		return nil
	}

	if strFlag != "" && iFmtFlag == "" {
		return fmt.Errorf("error: both --str and --if must be provided. Only str given: %s", strFlag)
	}
	if strFlag == "" && iFmtFlag != "" {
		return fmt.Errorf("error: both --str and --if must be provided. Only input format given: %s", iFmtFlag)
	}

	date := time.Unix(timestampFlag, 0)
	fmt.Println(applyFormat(date, ofmt))
	return nil
}